Want a Pompino gravel bike?
If you're not scared of a wee bit of modification, you can have one.
A 19mm 650b rim with a WTB Horizon 47mm tyre at 30 psi will fit with minimal clearance (a poofteenth of a mm) in a first generation Pompino rear (135mm).
Downsides:
It really needs a wee bit more dimpling, but that's something any anyone with a modicum of common sense and mechanical knowledge can do.
There will not be a lot of adjustment range unless you go extreme on the dimpling.
It would need some jiggery-pokery with the brakes because the rim surface will be 19mm lower. I'd use drum brakes and avoid the issue or make a horseshoe adapter. (Or even a disc brake adapter)
Upside:
The Pompino is already very nice on gravel and only limited by narrow tyres. The Horizon on a 650b rim is the same diameter as a 32mm on a 700 rim, so ride height, geometry etc is basically unchanged.
What is already a good bike will be even nicer.
I'm not going any further with this at the moment because I'm working on another project, but I thought the info would be useful to someone.
(I haven't tried this in a 120mm rear Pompino, but if anyone needs to know, I'll pull the wheel off my other Pompino and try it)
Of course Brant could save us all this bother by re-introducing the Pompino with the chainstays a smidgen further apart. 🙂
sounds good but have you considered the flexing of the frame and the subsequent rub? the Pomp is no better or worse than other steel frames but there will be movement
edhornby
...have you considered the flexing of the frame and the subsequent rub?...
That's why I recommend more dimpling on the chainstay even though the Pompino has one of the best set of singlespeed chainstays I've come across.
I had a belt drive conversion on mine, and had no problem with belts from flex, but you're right, I should have made it clear that I wouldn't ride it without dimpling it for a bit more clearance.
I really must check the 120mm OLD Pompino while I have the 650b tyre on the wheel. 🙂
